Abstract: A frictional transmission belt according to the present disclosure has a belt body wound around a pulley to transmit power. The belt includes a water absorptive fabric covering at least one side of the belt body that contacts with the pulley.

Abstract: A frictional transmission belt according to the present disclosure has a belt body wound around a pulley to transmit power. The belt includes a water absorptive fabric covering at least one side of the belt body that contacts with the pulley.

Abstract: A friction transmission belt includes a belt body looped over a pulley, and transmitting power. The belt body includes a rubber composition in which at least one of montmorillonite and magnesium carbonate is mixed. The friction transmission belt includes a fabric layer coating at least a surface, of the belt body, making contact with the pulley. The fabric layer has a portion making contact with at least one of the montmorillonite and the magnesium carbonate mixed into the rubber composition.

Abstract: A heavy-duty power transmission V-belt is so designed that respective upward projections each having an arcuate cross section of respective blocks are fixedly engaged with respective bottom-surface grooves each having an arcuate cross section of a tension member. The radius of curvature R2 of each bottom-surface groove is set larger than the radius of curvature R1 of the upward projection of the block (R2>R1) in the state that the tension member is put strait. Thereby, when the V-belt bends around a pulley, it can be avoided that a large local strain occurs at the bottom-surface groove. This allows a firmly fixed state of each block by the tension member to be maintained for a long time.